A Simple Mathematical Model for Flood Control by a Dry Dam
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At the same time that the estimated risk of natural disasters is increasing due to global warming, the capacity to prevent disasters in Japan has been weakened due to infrastructure degradation and population aging. To reduce the damage caused by flooding, flood control dams without a slide gate in a spillway, known as “dry dams,” have been planned and built on some sites in Japan. In this study, a simple mathematical model for flood control by a dry dam is proposed, aiming to encourage the construction of such dams. An implicit integral equation that is based on the continuity equation and simulates flood control by a dry dam is analytically derived. This equation can be easily solved by a spreadsheet program, making the mathematical models widely accessible, particularly to hydraulic engineers and students. The model’s results are compared with laboratory experimental results and the output of a numerical simulation. The results show that the accuracy of the model is quite good, especially in its prediction of the maximum water level of dam reservoirs, meaning that the peak discharge during a flood can be predicted to high accuracy by using this simple mathematical model.
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Tai, A., Oshikawa, H., and Komatsu, T. New Development of Functions of a Dry Dam for an Adaptation to Climate Change, Journal of Disaster Research. 2014. Vol.9, No.1, pp.78-85.
Sumi, T. Designing and Operating of Flood Retention ‘Dry’ Dams in Japan and USA, Advances in Hydro-Science and Engineering. 2008. Vol.8, pp.1768-1777.
Oshikawa, H., Hashimoto, A., Tsukahara, K. and Komatsu, T. Impacts of Recent Climate Change on Flood Disaster and Preventive Measures, Journal of Disaster Research. 2008. Vol.3, No.2, pp.131-141.
Shahmirzadi, M. E. M., Sumi, T. and Kantoush, S. A. Eco-Friendly Adaptation Design for Stilling Basin of Masudagawa Flood Mitigation Dam, Proceedings of the International Symposium on Urban Flood Risk Management (UFRIM). 2011. pp.69-74.
Nitta, F. and Maruta, M. An overview of the Nishinotani Dam (dry dam), Civil Engineering. 2010. Vol. 65, No. 2, pp.65-67 (in Japanese).
Nakagawa, M. Questioning the safety and environmental impact of dry dams (in Japanese).
Nakashima, Y., Oshikawa, H., and Komatsu, T. Study on Improvement in the Flood Control Ability of a Dry Dam, Advances in River Engineering. 2009. Vol.15, pp.417-422 (in Japanese).
Sumi, T., Kantoush, S. A., and Shirai, A. Worldwide Flood Mitigation Dams: Operating and Designing Issues, Proceedings of the International Symposium on Urban Flood Risk Management (UFRIM). 2011. pp.101-106.
Sumi, T. Dry Dam in Austria, Engineering for Dams, Japan Dam Engineering Center. 2009. No.277, pp.1-13 (in Japanese).
Sumi, T., Funabashi, S., and Shirai, A. Dry Dam in Austria –A Continued Report–, Engineering for Dams, Japan Dam Engineering Center. 2010. No.287, pp.16-28 (in Japanese).
Lamb, S. H. Hydrodynamics, 6th Edition, Cambridge. 1932.